Patients with epilepsy are at risk for sleep disorders for several reasons. Not only seizures but also interictal epileptiformdischarges (IEDs) may alter sleep organization. IEDs that result in arousals may disrupt sleep.

In one study of 14 patients, overnight-sleep EEG recordings showed bursts of generalized spike-wave complexes appearing in stages 2 and 3 of NREM sleep, sometimes occurring with K complexes.9 The discharges were associated with arousals. In some patients, discharges were associated with nonconvulsive body movements and resulted in significant sleep fragmentation with increased amounts of wakefulness and decreased amounts of REM sleep. Three patients treated with antiepileptic drugs showed reduced paroxysmal events during sleep, increased REM sleep, increased sleep efficiency, and a significant improvement in daytime sleepiness.

Not all IEDs result in arousals, however. Malow and colleagues found that IEDs in temporal lobe epilepsy were rarely associated with arousals from sleep and were most prevalent in deeper sleep stages (NREM stages 3 and 4). 10